1. Field of the Invention
The present invention relates to an adjustable steering damper intended to be used on a two or four-wheeled vehicle having a steering device comprising a handlebar or a steering wheel rotatable about a steering axis. Preferably the vehicle is a motorcycle, a snowmobile or an ATV. The steering damper is mounted at the steering device and is also coupled together with the frame or chassis by means of an attaching device. The damper is composed of an outer housing in which a main chamber is arranged, the main chamber comprising hydraulic fluid. The main chamber is partitioned into two chambers, for example by means of a delimiting part that is either rotatable about a first end or laterally displaceable in the chamber. The flow of the hydraulic fluid between the chambers is adjusted by a main valve and enables an adjustable damping of the relative motion between the steering device and the frame/chassis.
2. Description of the Related Art
A steering damper is mounted between the rotating handlebar or steering wheel of a vehicle and its fixed frame or chassis in order to damp shocks and violent movements that propagate from the front wheel(s) to the handlebar. When the steering damper is used on a motorcycle, the steering damper can also solve the problem of wobbling that may occur in a motorcycle at high speeds. Wobbling refers to the front wheel on the motorcycle beginning to oscillate about the steering axis with increasing amplitude. When the steering damper is used on a four-wheeled terrain vehicle, a so called ATV, the steering damper is primarily intended to damp the rapid steering movements caused by, for example, an asymmetric load on the wheels.
It has proven to be a problem to separate desired steering movements from undesired shocks caused by unevenness of the ground in a steering damper. In order to not create a delay in the steering movement when the driver turns the handlebar, it is desirable that this desired rotational movement is undamped. At the same time, undesired rotational movements caused by shocks from the ground should be damped as much as possible to minimize the risk of the handlebar being stricken from the hands of the driver. Thus, it is desirable to provide a steering damper that actively adapts the damping based on the cause of the movement.
In EP1248013 the problem is solved by a steering damper that by means of electronics senses and controls the damping on the handlebar depending on whether the movement is caused by the driver or the ground.
A steering damper that solves this problem by means of a principally mechanical solution is not known.